Rear Axle: Best way to clean differential (57 GHawk) without getting crud in from the tubes?

[bsrosell]

Hi,
I'm rebuilding my differential, but ONLY replacing the seals, outer axles bearings and removing the pinion bearing and cleaning it (assuming it's good). NOT taking out the innards of the differential due to the advice against it and the amount of careful tuning to get all the tolerances right (and not having all those tools the shop manual lists!)
My plan is to drain (done), remove the axle seals (done), clean that area good with a rag stuffed in axles tube to avoid getting junk caught in the differential bearings, and then after I finish wire-brusing, finally remove the rear cover and finish mopping out the remaining sludge and grease, and checking pinion gears and such.

But my question is this; those axle tubes are filthy; but I don't see how you can really clean them without getting the "grit" and garbage inside the differential.
My plan is once I remove the cover, to flush out with about 1/2 gallon of laquer thinner, letting it run out one side into a pail, then tipping the other way (after it drys) and doing the same thing, through the other axle tube, rotating the pinion and bearings the whole time I'm flushing it. Then I'll remove the dust-cover and pinion seal, remove THAT bearing and clean it, and with differential horizontal, dump the rest of my lacquer thinner through and drain through the pinion , rotating THAT bearing good to clean it.
Finally, pack as much bearing grease as I can in them (though I'll fill it with lube once I get it on the springs and mounted on the frame again).

I couldn't find anything about how to clean a differential (mine is standard, not Twin Traction, 57 Golden Hawk) on the Forum. I would think those axle tubes should be clean if lube is supposed to work its way down and keep the outer axle bearings lubed, but they are sure 60 year gritty/grimy now, and trying to push a cloth or something with brake cleaner, etc up them will only push crap up into the only bearings on the whole car that are NOT coming out and getting replace.
Thoughts/advice?
Thanks!

OH, almost forgot. Another thing; when I removed the right-side axle bearing, I first measured depth or rarther, how far it was sticking out past 'flush' from the axle housing flange. (should match shim pack, but haven't added them up yet), ideally the tolerance will be the .006" or whatever. BUT, if it is LESS, and I have to remove a shim, how do I get that bearing 'just a bit out" and matching the shim pack again? have to 'pull the axle' with the drum again, and tap it in just slightly less (to the new shim pack thickness? I forgot to measure it before I took the backing plate off, but hopefully it was right and I'll replace the exact same shims, so SHOULD be correct, unless worn......?

[r1lark]

I couldn't find anything about how to clean a differential (mine is standard, not Twin Traction, 57 Golden Hawk) on the Forum. I would think those axle tubes should be clean if lube is supposed to work its way down and keep the outer axle bearings lubed............?

In a Dana 44 axle (as well as a Dana 23, and 27) the gear lube for the ring/pinion does not provide lubrication for the axle bearings. Those bearings must be hand packed. (Earlier cars did have threaded holes with plugs, to allow the plug to be removed and a grease fitting installed to pump grease to the bearing.) The inner axle seal prevents the ring/pinion lube from getting to the bearings anyway.

As far as cleaning the axle tubes, I once had a rear axle that had some flakey rust buildup in the area of the vent hole. Ended up taking a long piece of all-thread rod, and about a 1" square piece of 1/8" plate and making a scraper. Drill a hole in the center of the plate to insert the all-thread into. One edge of the 1/8" plate should be radiused on a grinder, and the edge beveled to make a rudimentary scraper. This will allow you to scrape/pull the crud to the end of the axle housing where you can suck it out with a shop vac.

[bezhawk]

It's not hard to remove the center carrier despite not having a case spreader. Just mark the carrier bearing caps and replace the same position as they were. Then you can use a toilet brush on a long wooden dowel to clean inside. Then use kerosene or mineral spirits to flush out any remaining crud before reassembly. You dont need to worry about shims or any tolerances, because the shims are behind the carrier bearings, and stay put when you remove the carrier.

[bsrosell]

thanks;
a) mine is an early 57 (made Oct 56) so does have those threaded plugs. Yes, know those are greased but some comment (on forum I think but was reading shop manual too, can't remember) talked about greasing the bearings good until the tranny oil got to them. Seemed strange to me, as like you said, that's why you DO have a seal on both sides of the bearing. But I also question the design of axle bearings that are never intended to be greased again (on a 57, not 'sealed bearings' like today). But they lasted so I guess proof is in the pudding.

b) I already have differential all apart (ie: backing plates and shims and seals out, except pinion seal , have not gotten to that yet. You are saying I can remove the bolts on those two carrier bearings (marking them for exact replacement), and simply pull the whole thing out? so only the pinion gear would be left in place (or maybe that will slide out the front since I'm removing that bearing, if I can get a gear puller on the yoke or something and PULL it out, like I did with the rear axle bearings using the brake drum). Several people had told me to "leave the differential alone inside unless it is badly worn!", thus my plan...... But if I can remove it and not screw up clearances.....

c) I debated mineral spirits vs lacquer thinner , and had my wife pick up a gallon of lacquer thinner at last minute, thinking it is stronger solvent and more likely to cut that thick old cruddy grease. Wear organic vapor mask and gloves, so must be more potent.... Any reason NOT to use that instead?? As long as I take my safety precautions breathing it?

thanks
Barry

It's not hard to remove the center carrier despite not having a case spreader. Just mark the carrier bearing caps and replace the same position as they were. Then you can use a toilet brush on a long wooden dowel to clean inside. Then use kerosene or mineral spirits to flush out any remaining crud before reassembly. You dont need to worry about shims or any tolerances, because the shims are behind the carrier bearings, and stay put when you remove the carrier.

[bezhawk]

Yes, only the pinion will be left. I would think that the lacquer thinner to be harder to contain on a plastic drop cloth, as it would eat into it. Also, if you don't want to remove the pinion, (no need to) the mineral spirits wont harm the seal. Keep the nose of the pinion up as you clean it to keep the garbage out , then rinse afterwards to be sure it's clean. There are shims at the pinion that can be disturbed by removing as they are not held captive by the bearings (like the carrier).

[r1lark]

But I also question the design of axle bearings that are never intended to be greased again (on a 57, not 'sealed bearings' like today).

Barry, the rear axle bearings do have to be repacked periodically.......the shop manual has the frequency, can't remember it off the top of my head. The cars with the plugs had a specific frequency for putting in zerks and pumping some grease in -- but not every oil change/grease job!

[bsrosell]

Ok, thanks, back to the mineral spirits, completely forgot about the plastic-melting, my ice cream buckets would be a mess pretty quickly and don't care to have it running all over my shop floor! My pinion seal is getting replaced, leaks pretty easily when differential got tilted down, probably dried out like all the rest I've replaced, but the plastic melting is an issue. Plus, now that I know I can get at most of the part to clean decently, I'm not as concerned about 'powerful solvent'. Appreciate your tips.
Barry

Yes, only the pinion will be left. I would think that the lacquer thinner to be harder to contain on a plastic drop cloth, as it would eat into it. Also, if you don't want to remove the pinion, (no need to) the mineral spirits wont harm the seal. Keep the nose of the pinion up as you clean it to keep the garbage out , then rinse afterwards to be sure it's clean. There are shims at the pinion that can be disturbed by removing as they are not held captive by the bearings (like the carrier).

[bsrosell]

ah; have not read that part of the shop manual yet, kind of going in order of the tasks I'm doing (diassembly at this point :-). Glad mine has the plugs though, beats pulling the backing plate off to get at them! Thanks.
Barry

[jackb]

don't trust the old cork in the outer axle seal. You'll probably push the grease all over the brake shoes.... With today's grease, you should get 50K miles out of the re-pack.....That's if you're driving the vehicle...I'd advise against the zerks... you cannot tell where the grease is going...!

[bsrosell]

don't trust the old cork in the outer axle seal. You'll probably push the grease all over the brake shoes.... With today's grease, you should get 50K miles out of the re-pack.....That's if you're driving the vehicle...I'd advise against the zerks... you cannot tell where the grease is going...!

thanks; already have the old seals out and have new bearings/cups as well for the outer axle (and new seal for pinion).
I doubt I'll ever need to put in zerks back there, agreed!! :-)

[56Golden]

Can't help with suggestions on cleaning as I took my complete axle (less brake backing plates) to a good local 4WD shop and had them also change ratio (ring/pinion) and add TT. Could have done all that myself except for Magnafluxing the axle shafts to check for cracks. Well worth the $$$ for the piece-of-mind running with 60 year old shafts and their unknown history.

[bsrosell]

Ok, show my ignorance here but I have never personally had anything magnafluxed, though know my engine rebuilder (since gone) on the '26 Model-T Ford did it; do they automatically do it on engine tear-downs and cook-outs so anyone who rebuilds engines has the capability?

Can't help with suggestions on cleaning as I took my complete axle (less brake backing plates) to a good local 4WD shop and had them also change ratio (ring/pinion) and add TT. Could have done all that myself except for Magnafluxing the axle shafts to check for cracks. Well worth the $$$ for the piece-of-mind running with 60 year old shafts and their unknown history.

[Ron Dame]

I'm trying to find that stinkin' vent hole (Dana 44, 1963 Avanti). The left tube is crudier that the right, so that seems likely, but in scraping the heavy junk off, I apparently plugged it.. if it wasn't already.
On the Champ, also a 1963 with a Dana 44, it was on the left, and at about 1:00 maybe 6" from the spring. Not here. Nor at 4:00 like another post mentioned.
Are Avanti's different? I wouldn't think so for the diff, but where is that hole?

[Jeff_H]

Mineral spirits paint thinner is my usual degreaser/solvent for stuff that this. A lot cheaper than lacquer thinner and does not evaporate so fast. You could probably use a bottle brush with an extension attached to a slow drill to help remove stuck on deposits inside the tubes (before seals & bearings are installed). Put the housing w/cover off facing down so stuff can drain into a pan. You may want to try one of these or similar too:

https://www.harborfreight.com/engine-cleaning-gun-68290.html

I've used a similar one that had a screw on tank on it instead of the siphon hose. Use safety glasses so you don't get back spray in the eye!

[Ron Dame]

thanks, but where do I find that stinkin vent hole? I've cleaned the housing, and still can't find it.